It is well known in the art to launch a missile from a canister. Missiles are launched from canisters using either a “hot” launch technique or a “cold” launch technique.
During hot launch, the missile's motor ignites while the missile is in the canister. The motor provides the thrust that is required to propel the missile from the canister. During cold launch, an ancillary system is used eject the missile from the canister; that is, the missile's motor does not ignite until after the missile leaves the canister. In some cold launch systems, the ancillary system comprises a sled or base upon which the missile rests. During launch, the sled and the missile are accelerated toward the front end of the canister. The sled is abruptly stopped at the forward end of the canister while the missile exits the canister due to its inertia.
A restraint/release mechanism (hereinafter simply “release” mechanism) normally secures the missile within the canister prior to launch to prevent damage to the missile and to maintain its orientation within the canister. Of course, this mechanism must release the missile for launch.
Hot launch systems employ either an active release mechanism, such as explosive bolts, or a passive release mechanism, such as a combination of springs and latches. When a passive mechanism is used, missile motor ignition is often used to trigger the passive mechanism into release. See, for example, U.S. Pat. No. 4,550,640. Of course, that technique is only suitable for hot launch, since the missile does not ignite within the canister during cold launch. Cold launch systems, especially those that include a sled or base to accelerate the missile, often use two release mechanisms, which are typically active mechanisms. The first mechanism releasably couples the sled or base to the canister and the second mechanism releasably couples the missile to the sled.
There is a risk that the release mechanism will not release during launch. This results in a restrained firing, which can cause damage to the canister, canister internals, and the missile itself. This risk is typically greater for a cold launch system than a hot launch system, and the risk is especially elevated for a cold launch system that uses two release mechanisms.
There is a need, therefore, for a release mechanism that substantially prevents the possibility of a restrained firing during launch of a canistered munition.